Session V - Knee / Tibia

Fri., 10/11/13 Knee/Tibia, PAPER #64, 3:16 pm OTA 2013

Does a 6-Month Wait Before Reoperation Improve Tibial Nonunion Rates? A Comparative Examination of Patients Not Enrolled in SPRINT

Carol A. Lin, MD, MA; for the SPRINT (Study to Prospectively Evaluate Reamed
Intramedullary Nails in Patients with Tibial Fractures) Investigators;
Hennepin County Medical Center, Minneapolis, Minnesota, USA

Purpose: The SPRINT trial had lower than expected reoperation rates for nonunion based on previous literature (5% vs 11%), and it was hypothesized that the 6-month prohibition against reoperation was a major contributing factor. We compared rates and timing of reoperation in a subset of patients enrolled in SPRINT to those who were eligible but not enrolled to evaluate the effect of the 6-month waiting period and assessed the influence of a large randomized controlled trial on a parallel observational cohort.

Methods: The billing records of 6 of the SPRINT centers were searched for current procedural terminology (CPT) codes indicating intramedullary nailing of a closed tibia fracture and reoperation for fracture healing. Patients were grouped into SPRINT and unenrolled patients, and the rate and timing of reoperation were compared. A Fisher exact test was used to compare categorical variables and a Student t test was used to compare continuous variables. P <0.05 was considered significant.

Results: 114 unenrolled patients were compared to 328 patients enrolled in SPRINT from the 6 sites. 105 (92%) underwent reamed nailing versus 167 (51%) of the SPRINT patients (P <0.001). There were 7 reoperations (6.1%) in unenrolled patients versus 18 (5.5%) in SPRINT patients (odds ratio [OR] 1.13, 95% confidence interval [CI] 0.39 to 2.92; P = 0.815). There was no difference in the time to reoperation for nonunion (6.3 vs 6.8 months, 95% CI of the difference –3.75 to 2.65; P = 0.701). The proportion of patients who underwent reoperation before 6 months was substantially but not statistically significantly higher in the unenrolled patients (28% vs 43%, OR 1.9, 95% CI 0.20 to 16.53; P = 0.640).

Conclusion: Patients not enrolled in the SPRINT trial but who were treated at the same centers had similarly low rates of reoperation for nonunion following intramedullary nailing for closed tibial shaft fractures. A 6-month waiting period may explain the lower than expected rates. It is possible that clinical trials associated with improved outcomes may beneficially influence the care of nonenrolled patients; however, the extent of this influence requires further investigation. Parallel observational studies can be useful adjuncts to randomized controlled trials.

Alphabetical Disclosure Listing

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.